Draft control



July 13, 1937. F, R, HINER 2,086,617

DRAFT CONTROL Filed June 21, 1935 2 Sheets-Sheet l 4July 13, 1937. F R, HlNER 2,086,617

DRAFT CONTROL Filed June 2l, 1935 2 Sheets-Sheet 2 .L9 /J- .L Z

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Wfnass l INVENTOR. I E/'nz @EL Ml a@ ATTORNEYS.

Patented July 13, 1937 UNITED STATES PATENT OFFICE DRAFT CONTROL Application June 21, 1935, Serial No. 27,741

Claims. (Cl. 236-45) The present invention relates to draft controls, or means for controlling or checking the draft of fluid through pipes, iiues and the like, particularly furnace smoke pipes; and its object is, gen- 5 erally, to provide means and devices of that character improved as hereinafter described; and more particularly, to provide such a control automatically operated by the draft itself; and further, to provide such a Control which may be nicely adjusted for operation by a predetermined degree of draft; and further, to provide such a control whereby the draft through a furnace may be maintained approximately constant and at a predetermined degree, although the draft through its smoke pipe or chimney may fluctuate considerably; and further, to provide in combination with such a control, means for creating a forced draft during predetermined conditions; and further, to provide certain specic meansI for carrying out such objects.

These and any other and more specific objects hereinafter appearing are attained'by and the invention nds preferable embodiment in, the structure and mechanism particularly described in the body of this specification and illustrated by the accompanyingdrawings, in which:

Figure 1 is an elevational view of portions of a furnace and of a chimney with a smoke pipe extending therebetween provided with my draft control;

Figure 2 is an elevational side View of said control, its damper in position partially closing the smoke pipe which is shown in transverse section taken on line 2 2 of Figure l;

Figure 3 is a View similar to Figure 2 (some- What enlarged) showing the damper in position fully opening the smoke pipe which is shown in transverse section taken on line 3-3 of Figure 4;

Figure 4 is a top plan View thereof;

Figure 5 is a sectional view of the same taken on line 5 5 of Figure 3;

Figure 6 is an elevational view of the same, partially sectioned on line 6 6 of Figure 3;

Figure 7 is an elevational view similar to Figure 1, and showing draft-forcing means;

Figure 8 is an elevational side View (enlarged) of a portion of said control and electrical means for initiating the draft-forcing means;

Figure 9 is an elevational front view of a portion thereof, partially sectioned on line 9 9 of Figure 8.

In these drawings (Figures 1 and 7) my draft control is shown applied tothe smoke pipe 2 leading from a furnace 3 to the chimney 4, although this control may be applied to various pipes, Ilues or passages to control fluid flow therethrough. In the illustrated application, the draft control, indicated generally I, comprises a hollow member or body made of sheet metal or the like and having iiat parallel opposite walls 5, B and curved 5' walls I, 8 connected thereto, the walls 5, 5 extending at right angles to the smoke pipes axis. In this relation said body is secured to the smoke pipe by suitable means as by one or more threaded bolts 9 extending through the outwardly 10 turned iianges I9 of the mutually adjacent ends of the walls l, 8, these walls being curved over the smoke pipe to embrace one side I! thereof and the parallel walls 5, 6 having their free inner edges I2 concave correspondingly with the smoke l5 pipes form to embrace the opposite side i3 thereof, in which position said body is tightly clamped on the smoke pipe by turning down the nuts I4 of said bolts.

Said body contains an oscillatory damper 20 made of sheet metal or the like, comprising a at vane portion I5 extending parallel with the walls 5, 6 and an arm portion I5 pivotally mounted at I1 on said body so that the damper may be swung to carry the vane portion inwardly-outwardly of the smoke pipe through an arcuate slot opening in the side thereof, or through the gap I8 between adjacent lengths or sections I9 thereof as shown, said lengths being overlapped and connected by the bodys wallsv l, 8 and said gap 30 closed thereby except at the smoke pipes side i3 through which the vane portion is moved.

Said arm portions lateral edgesv 22 are in approximate contact with the inner surfaces of the walls 5, 6 and the arms free inner end 25 in 35 approximate contact with the inner surface of the wall 'I in the dampers swinging movement.

It will be seen that said hollow body member forms a chamber open at 23 to atmosphere and open through said gap into the smoke pipe, this 40 chamber forming a channel along which the arm portion I6 moves as a closure therefor.

It will be seen that the draft through the smoke pipe in the direction of the arrows (i. e. from the furnace to the chimney) diminishes, to a greater 45 or less degree depending on the force of the draft, the fluid pressure in said chamber thus causing the damper to swing inwardly by reason of relatively greater pressure on the closure arms outer side, and that this movement carries the vane 50 portion I5 through said gap i8 into the smoke pipe, to a correspondingly greater or less degree depending on this draft force, thus diminishing the cross-sectional area of the smoke passage and checking and controlling the draft. 55

To adjust the desired movement of the damper to the force of the draft, the arm portion I6 has an outwardly extending rod 28 along which a block 29 is slidable to positions clamped thereon by the set screw 38, and a counterweight 3I has a screw shank 32 threaded in this block, so that the weight may be moved to a nicely adjusted position.

Inasmuch as the draft through the chimney itself fiuctuates greatly and suddenly by reason of varying rarefaction of gases therein or changing winds which create a suction from its mouth, and in order to maintain the draft through the furnace itself as constant as possible, my control is made essentially a part of that portion or section of the smoke pipe which extends between the furnace and the partially closed vane portion I5 rather than a part of the smoke pipe which extends beyond said vane. To effect this end, the said vane portion is located adjacent I that lateral edge 21 of the closure arm which is remote from the furnace, so'that the body members said chambery or channel opens into the smoke pipe between the furnace and said vane portion.

If the counterweight 3l be adjusted to the desired position (say to that shown in Figure 3 wherein the smoke pipe is entirely open), the draft through the furnace will not be diminished ,by the draft through the chimney unless and comparatively slight fluctuations in the chimney draft nor immediately thereafter, for ,myv control does not respond to such fluctuations nor immediately the same occur, the gases in the chimney being elastic and of varying rarefaction.

A spring 48 cushioning the falling movement of the closure arm I6, and a rigid stirrup-49 in which thev pivot bolts I'I1 are mounted, are shown in Figures 5 and 6. y

It will be vseen that inasmuch as the damper is pivot'ally mounted on the axis Il which'is outside the smoke pipe and on the outer side of closure arm (as shown in Figures 2 and 3), this `pivotal mounting is not fouled by smoke or soot in the pipe nor corroded by gases therein.

Akrotary fan indicated at 33 (Figure 7) having a discharge pipe 34 ventinginto the smoke pipe may be employed for creating a forced draft therein. This fans motor indicated at 35 in an electric circuit 35 is energized'by closing a mercury switch of the ordinary form, sho-wn in Figures 8 and 9,"in which the mercury tube 3l' whose mounting 38 pivoted at 39 is vsuddenly turned to open or closed positions by the spring 48 connecting said mounting with the actuating lever arm 4I pivoted at 42. This armis connected by a link 43 with the dampers rod 28 which has a wrist pin 44 engaging slidably in the links slot 45.

The switch. is operated by the damper in the following manner: Assuming the damper to be open, its vane portion I5 withdrawn from the smoke pipe, the dampers rod 28\will assume the position shown in solid lines inFigure 8 ,j assuming that the chimney is cold, no draft or insufficient draft therein, the lever arm 4| may be manually turned to the position seen in said View whereby the switch is closed, the motor energized and a forced draft thereby created by the fan. As the draft increases, the closure arm I6 is drawn up as hereinbefore explained checking the draft; and the rod 28 falling causes its wrist pin 44 to strike the bottom end 4E of slot 45 thereby opening the switch and stopping the motor and the fan. If the draft then diminishes sufficiently so that the closure arm I6 falls, its rod 28 rises yuntil the wrist pin strikes the upper end 4l of said slot again closing the switch.

It will be seen that this fan and operating switch are employed for extreme draft conditions,

and that during the usual operation of my draft control the wrist pin 44 oscillates along the slot 45 without striking either end thereof.

It will also be seen that when the vane portion l5 is inpartially closed position shown in Figures 1 and 2, the direction of the draft is somewhat deflected from the closure arm I6 by the vanes inner edge 26 thus tending to relieve the pressure on the inner side of said closure arm and causing the vane portion to swing farther inwardly, said vane portion being located adjacent that lateral edge of the closure arm which is remote from the furnace.

The invention being intended to be pointed out in the claims, is not to be limited to or by details of construction and arrangement of the particular embodiment thereof illustrated by the drawings or hereinbefore described.

I claim: y

1. In a draft control for a pipe comprising sections spaced endwise to provide a gap therebetween; a hollow body member secured to said sections and comprising parallel sides extending in a direction transversely ofthe sections and having edges ttingly engaging one side thereof, and curved sides one of which fittingly engages the opposite sides of said sections, said member forming a channel of substantial width in the pipes axial direction open at spaced points to y the atmosphere and into said gap; a damper oscillatingly-swingably mounted on` an axis parallel with the pipe,.comprising a closure portion for the channel oscillatingly movable therealong between said points by relative degrees of fluid pressure on its opposite sides, the damper including also a vane portion movable through said gap inwardly of the pipe by kincreased draft therein and oppositely by decreased draft therein, the vane portionbeing connected tothe clossure portion adjacent the lateral edge thereof which is remote from the inlet end of the pipe.

2. A draft control for a pipe having an opening extending through and partially around its side, comprising: a hollow body member extending radially from said side having side walls disposed at approximately right angles to the pipe and forming a channel open at spaced points to the atmosphere and into the pipes opening respectively; a control member in the body member `having a damper vane portion extending in a direction at approximatelyv right angles to the pipes axis-and adapted to be moved through the Apipes opening, and having also an arm portion extending laterally parallelly with said axis and being swingably mounted on an axis parallel with the pipes axis for oscillatory movement in and along the channel between said points and forming a closure for the channel prohibiting entrance of air from the atmosphere to said pipe,

said control member being movable inwardly by the atmospheric pressure relatively greater than fluid pressure in the pipe to carry the vane portion inwardly of the pipe and movable outwardly by fluid pressure in the pipe relatively greater than the atmospheric pressure to carry the vane portion outwardly of the pipe.

3. A draft control for a pipe having an opening extending through and partially around its side, comprising: a`hollow body member extending radially from said side having side walls disposed at approximately right angles to the pipe and forming a channel open at spaced points to the atmosphere and into the pipes opening respectively; a control member in the body member having a damper vane portion extending in a direction at approximately right angles to the pipes axis and adapted to be moved through the pipes opening, and having also an arm portion extending laterally parallelly with said axis and being swingably mounted on an axis parallel with the pipes axis for oscillatory movement in and along the channel between said points and forming a closure for the channel prohibiting entrance of air from the atmosphere to said pipe, said control member beingmovable inwardly by the atmospheric pressure relatively greater than fluid pressure in the pipe to carry the vane portion inwardly of the pipe and movable outwardly by fluid pressure in the pipe relatively greater than the atmospheric pressure to carry the vane portion outwardly oi the pipe, said vane portion joining said arm portion adjacent the lateral edge thereof which is remote from the inlet of the pipe.

y 4. A draft control for a pipe having an opening through its side, comprising: a hollow body member extending radially from said side forming a channel open at spaced points to the at- 40 mosp-here and into the pipes opening respectively; a control member in the body member havy ing a damper vane portion adapted to be moved through the pipes opening and having also an arm portion at approximately right angles to the vane portion and swingably mounted on an axis parallel with the pipe for oscillatory movement in and along the channel between said points and forming a closure for the channel prohibiting entrance of air from the atmosphere to said pipe, said control member being movable inwardly by the atmospheric pressure relatively greater than fluid pressure in the pipe to carry the Vane portion inwardly of the pipe and movable outwardly by fluid pressure in the pipe relatively greater than the atmospheric pressure to carry the vane portion outwardly of the pipe.

5. A draft control for a pipe having an opening throughits side, comprising: a hollow body member extending radially from said side forming a channel open at spaced points to the atmosphere and into the pipes opening respecl tively; a control member in the body member having a damper vane portion adapted to be moved through the pipes opening and having also an arm portion at approximately right angles to the vane portion and swingably mounted on an axis parallel with the pipe for oscillatory movement in and along the channel between said points and forming a closure for the channel prohibiting entrance of air from the atmosphere to said pipe, said control member being movable inwardly by the atmospheric pressure relatively greater than fluid pressure in the pipe to carry the vane portion inwardly of the pipe and movable outwardly by iiuid pressure in the pipe relatively greater than the atmospheric pressure to carry the vane portion outwardly of the pipe, said vane portion joining said arm portion adjacent the lateral edge thereof which is remote from the inlet of the pipe.

FRANK R. HINER. 

